Rotary compressors or pumps, in combination with hydraulic controls, and mechanical controls in co-ordination therewith



Aug. 9, 1955 F. KEPKA ETAL 2,714,853 ROTARY COMPRESSORS OR PUMPS. IN COMBNATION WITH HYDRAULIC CONTROLS, AND MECHANICAL CONTROLS IN CO-ORDINATION THEREWITH Filed Nov. 5, 1950 8 Sheets-Sheet l Aug. 9, 1955 ROTARY COMPRESSORS OR PUMPS,

Filed Nov. 3, 1950 F. KEPKA ET AL IN COMBINATION WITH HYDRAULIC CONTROLS, AND MECHANICAL CONTROLS IN CO-ORDINATION THEREWITH 8 Sheets-Sheet 2 Allg 9, 1955 F. KEPKA ET AL ROTARY COMPREssORs OR PUMPS, IN COMBINATION WITH HYDRAULIC CONTROLS, AND MECHANICAL CONTROLS IN CO-ORDINATION THEREWITH 8 Sheets-Sheet 3 Filed NOV. 5, 1950 Aug- 9, 1955 F. KEPKA ET AL 2,714,858

ROTARY COMPRESSORS OR PUMPS, IN COMBINATION WITH HYDRAULIC CONTROLS, AND MECHANICAL CONTROLS IN CO-ORDINATION THEREWITH Filed Nov. 3, 1950 8 Sheets-Sheet 4 Aug. 9, 1955 F. K ROTARY COMPRESSOR-S EPKA ET AL OR PUMPS, IN COMBINATION WITH HYDRAULIC CONTROLS, AND MECHANICAL. CONTROLS IN CO-ORDINATION THEREWITH Filed Nov. I5, 1950 8 Sheets-Sheet 5 C /A/l/f/V F. KEPKA ET AL ROTARY COMPRESSORS OR PUMPS Aug. 9, 1955 2,714,858 IN COMBINATION WITH HYDRAULIC CONTROLS, AND MECHANICAL CONTROLS IN CO-ORDINATION THEREWITH 8 Sheets-Sheet 6 Filed Nov. 3, 1950 202 2% 5pm/5N fg 6a INVENTORS` Wy M7176@ Aug- 9, 1955 F. KEPKA ET AL 2,714,858

ROTARY COMRRRSSORS OR PUMPS, IN COMBINATION WITH HYDRAULIC CONTROLS, ANO MECHANICAL CONTROLS IN CO-OROINATION THRRRWITH 8 Sheets-Sheet '7 Filed NOV. 3, 1950 Allg- 9, 1955 F. KEPKA ET AL 2,714,858

ROTARY COMPRESSORS OR PUMPS, IN COMBINATION WITH HYDRAULIC CONTROLS, AND MECHANICAL CONTROLS IN CO-ORDINATION THEREWITH Filed Nov. 3, 1950 8 Sheets-Sheet 8 5 5 Jag I N VEN TORS Mit/@Q United States Patent O ROTARY COMPRESSORS OR PUIMPS, IN COMBINA- TION WITH HYDRAULIC CONTROLS, AND ME- CHANICAL CONTROLS IN CO-ORDINATION THEREWITH Frank Kepka, Altadena, and Jean A. H. Barkeij, San Clemente, Calif.

Application November 3, 1950, Serial No. 193,828

27 Claims. (Cl. 10S- 136) This invention relates to rotary compressors, which take in a volume of iluid between its vanes and carry it around to be squeezed out from between the vanes when they approach the position in which one of each set of two vanes approaches its most inward position in the body of the rotor. It is understood that the wordcompressor--includes the word-pump, as it will be shown that the same device with certain minor changes or under certain conditions may be equally used to pump liuids instead of air or gases. It is equally understood that the mechanism shown could be used to transmit power from a prime mover to a driven mechanism by duplicating the pump shown, one driven by said prime mover the other being connected to the driven mechanism. The inlet of the second pump would be connected to the outlet of the said first pump, and the outlet of the second pump would be connected to the inlet of said rst pump, establishing a circulation of oil (or any other liquid) from one pump to the other.

It is further understood that the principle of the present pump may also be applied on any rotating mechanism incorporating a flywheel or any cylindrical clement having arranged therein pistons and weights attached thereto7 to move said pistons and weights towards and from the axis of said flywheel to decrease or increase the centrifugal and inertia forces thereof by moving them by hydraulic forces operating simultaneously on all pistons in opposite directions.

In this latter respect we draw the attention of readers of this patent to the German Patent No. 100,943, January 20, 1899, in which such pistons and weights attached thereto are moved in one direction away from the axis of the ywheel by springs and are moved towards the axis by fluid pressure. In the present system, as explained hereinafter more for application of this principle on compressors for fluids or huid-pumps, we move the weights and pistons away from the axis by hydraulic force and move them against toward the axis by hydraulic force. We use always one of two closed chambers, each of which may receive a hydraulic pressure independently of each other, or they may receive hydraulic pressure simultaneously. They may be entirely separate from each other, they may be in constant communication with each other, or they may be separated from each other by valves operating under fluid pressure.

In so far as the centrifugal force tends to throw movable weights and pistons always towards the periphery or circumference of the rotating mechanism, one huidpressure chamber communicating with each of said pistons (moving in cylinders as shown) and opertaing on one side of said pistons, forcing them towards the axis of this rotating mechanism would be suiiicient. The application of any spring (helical or otherwise) as shown in said German Patent 100,943 are totally superfluous and detrimental, because sudden accelerations of the rotating mechanism exert too great forces on the pistons, weights and further mechanism connected therewith. The applicants propose to arrange the pistons and weights iii ICC

radially and as units in any rotating mechanism, and to move said units simultaneously by a single or double hydraulic force towards and away from its rotating axis.

They further propose to retain the hydraulic iluid by a self closing valve (as shown for instance at 2f in Fig. 2) at the inlet side to the hydraulic chamber, common to all pistons and weights connected thereto, and to retain the hydraulic iluid also at the drainage side from said chamber. The latter drainage side should be preferably under control so that the fluid may be drained from said hydraulic chamber to allow said pistons and weights to assume a position further away from or closer to the axis of the rotating mechanism.. This latter valve may be under control of a centrifugal governor, see Fig. l0 (to be described later) or may be under manual control. Either control operates to regulate the tension of the helical spring keeping said valve closed and said hydraulic chamber closed.

ln case two hydraulic chambers are used, the fluid pressure in one chamber would drive the pistons and weights outwardly from the axis of the rotating mechanism, and the fluid pressure in the other chamber would drive the pistons and weights (called piston-weights in the claims hereto attached) towards the axis.

In case the two chambers would be in communication with each other through a valve Ze-e-e (or through any permanent passage, see Fig. 9) as shown in Fig. 2, the surface of pressure on the pistons must be greater in the inner (or central) chamber 11 than in the outer chamber 2c, in order to move the piston-weights outwardly. The regulation of the tension of the spring of valve 2g would empty the outer chamber and the pistonweights would move. By closing the two chambers from each other, separating them, the pressure must be fed into the two chambers separately through valves and drained separately,

These different modifications are obvious from the principle disclosed in the drawings of a compressor or pump. Although in a pump as shown, the vanes and pistons (or piston-weights) are moved from and towards the axis of the rotating rotor, and at different distances therefrom in order to create a pump action. Nevertheless the principle remains the same as the hydraulic pressures are concerned. In the pump-type of rotating mechanism the pistons and weights are controlled by the pressure in one or two closed chambers, and additional mechanism in the form of bearings to retain these pistons and vanes (weights) at the proper distance from the inner surface of the stator is, of course, totally superfluous in any kind of flywheel, or rotating mechanism, in which said pistons and Weights must assume all exactly the same position from the center or axis thereof.

In big diesel engines, steam-engines with huge ilywheels, steam turbines, or steam turbines driving mechanism (f. i. locomotives) with a great reduction of speed, it would be of extreme advantage to have ilywheels in which the inertia, heaped up therein at various speeds, could be varied greatly during the running thereof. Therefore the applicants do not limit themselves in this application in the single variation shown, but consider it applicable on a great variety of various rotating mechanisms, with the limitations set forth in the appended claims.

In Barkleys prior Patent No. 2,209,012 of July 23, 1940 (applied for on October 27, 1933, Ser. No. 695,459, renewed January 23, 1939) is disclosed a similar hydraulic control, eventually in co-ordination with mechanical controls (for synchronization), although it refers to such means in general to increase and decrease the compression ratio of internal combustion engines (see espec. the object described on page l, column l, lines 34 to 39 thereof). Subsequently the same applicant makes the 3 application No. 346,258 of July 17, 1940, now abandoned, using the same type of hydraulic means, and the same co-ordination to vary the pitch of blades of a propeller for airplanes. We will describe shortly the main points of similarity of these means in view of U. S. C. section 112, third paragraph in particular. In Patent No. 2,209,012, Pig. 12, he applies the hydraulic pressure through passage 75b in Fig. 12 to drive the pistons 80 against the centrifugal force towards the axis of the rotating mechanism, and applies another hydraulic pressure through passage 75a towards the inner side of the same piston to help the centrifugal force to bring the piston 80 away from the axis of the rotating mechanism. The gears 75 shown in Figs. 12-13 show that the mechanical means are further provided to co-ordinate the motion of the pistons 80 for the various throws in the crankshaft.

In the second application No. 346,258 of July 17, 1940, he used a single or two hydraulic forces operating on 3 pistons, receding from the axis of the rotating mechanism and approaching the axis of the rotating mechanism, and this mechanism rotated the blades of an airplanepropeller to vary their pitch in order to obtain a varying grip of the blades of the propeller on the air to drive an airplane through the air. Here the co-ordination of the hydraulic forces on the rotating blades is also effected by the gears between the hydraulic pump and the 3 blades of the propeller.

The only difference between the former application of this principle as patented in Patent No. 2,209,012, and the present application is that all the pistons or elements 80 are driven simultaneously from the axis, and towards the axis, of the rotating mechanism by the single or two hydraulic pressures, in the former application thereof, while in the present application of said principle half of the pistons move away from the axis of the rotating mechanism and the other half towards this axis under the influence of a single or two hydraulic pressures operating on the pistons. In application 346,258 however, the pistons move partly away and partly towards the axis of the rotating mechanism, depending upon number of pistons used. This difference is merely due to the mechanical details of the mechanism on which the same principle is applied, and is merely modified in view of the functions which each rotating mechanism should perform.

The system in all three applications (including the present continuing one) includes a rotating mechanism, including a rotating body or element, elements or pistons in said body tending to recede from the axis of the rotating mechanism under centrifugal force, including the fluid of the hydraulic pressure in combination therewith to move these elements or pistons by said hydraulic pressure toward the axis of the rotating mechanism, and in combination further with mechanical means to coordinate the motion of the elements or pistons and to co-ordinate the predetermined positions of said elements or pistons.

A single hydraulic pressure can be used to move these elements or pistons towards the axis of the rotating mechanism or away from the axis thereof. In so far as the centrifugal force operating on these elements or pistons (plus the corresponding uid in the corresponding cylinders) when operating away from the axis of the rotating element, a lower hydraulic pressure could be used to move them away from the axis of the rotating mechanism. The important point however is that the total motion of the pistons towards and from this axis is performed by hydraulic pressure; and not partly by counterweights, springs, etc. as shown in the Ludenia reference of record herein and other patents referring to propellers. The motion of the pistons must be further co-ordinated by mechanical means besides the equal hydraulic pressure on all pistons, in order to retain them exactly at predetermined postions away from this axis. It is further irrelevant whether part of the pistons moves CIX towards this axis and part away from this axis, as long as the pressure is simultaneously and uniformly exerted on the pistons. In the Patent No. 2,209,012 (J. A. H. Barkeii, sole owner) Barkeij prefers to use two pressures, with a differential between them, on opposite sides of the pistons 80 in Fig. 13, and the positions of all the pistons of all the crankthrows, are predetermined and co-ordinated by the gearing between the various throws. But a single pressure could be used alternately on the upper side and underside of the pistons.

In the application 346,258 of July 17, hydraulic mechanism for an airplane propeller, Barkeij used three cylinders with pistons reciprocating therein, and a single or two hydraulic pressures operating on these pistons to move the blades to obtain a variable pitch, instead of a variable compression in Patent No. 2,209,012. By reversing the rotation of the mechanism, or motor, moved by said hydraulic pressure, Barkeij could use obviously only one hydraulic pressure on one side of the pistons. The main point here again was that the motion of the pistons, and the rotation (motion) of the blades were co-ordinated by mechanical means co-operating with the hydraulic means and reversely, so that the blades of the propeller would move in unison. The motion of the pistons` under hydraulic pressures, which is radially from and towards the axis of the rotating mechanism, can be transformed into a rotary motion of the blades by any kind of gearing or helical splines. Even if the pistons were attached to the blades themselves, and the movement of the blades were from and to the axis of the circular element, in which these blades would be radially arranged, the rotation, simultaneous with that radial motion, could be effected by helical splines, above or below said pistons, operating, of course, on a stationary helical spline.

All these various modifications are within the Capacities of men versed in the arts, i. e. experts, once the basic principle of all of these modifications has been explained, as the appplicant did in said prior patent and application 346,258.

Therefore the exact scope of the appended claims governs entirely the scope cf these equivalent, parallel, similar, and closely related inventions, disclosed herein and in the two prior applications of the joint inventor, named in said prior patent and application.

The present type of compressor will not need any lubrication except in the inner part of it for the mechanism is designed to eliminate any friction between the wall of the stator and the vanes of the rotor.

Although the vanes do not have to touch actually the wall of the rotor on account of a minimum clearance kept between the outermost tips of the vanes and the stator or body of the compressor, nevertheless hereinafter will be spoken of this small clearance as a seal.

Low outlet pressures at constant speed and a great continuous discharge at high speeds is a feature of the present compressor.

It is a further object of the present invention to reduce the noise to a minimum, and to raise the possible speed to a maximum with a minimum of wear and tear on the varies.

lt is a further object to control the position of the vanes at all times in any position with respect to the rotor hydraulically; it is a further object to control their Aposition at all times mechanically; and it is a further object to control their position at all times mechanically and hydraulically, in any of the three types shown herein.

The accompanying drawings show a new type of vaneblower in accordance with the new principles disclosed thereby and the following description.

Fig. 1 is a vertical sectional elevation of one type of compressor and represents the Fig. 2 on the three or six various section lines 1--1 shown therein.

Fig. 2 is a vertical lengthwise section of the same compressor on the section line 22 of Fig. 1.

Fig. 2a shows diagrammatically an arrangement whereby a thermostat, registering the heat of thel wall of the stator or of certain bearings of the stator,` may regulate the amount of oil inducted by a pump in the inside of the rotor. i

Fig. 3 shows a vertical section of Fig. 2 on the section line 3--3.

Fig. 4 represents a modified type retaining the features of the type of Figs. 1 to 3, in which a lighter type of vane may be used, the clearance of which is regulated in a way different from that in Figs. l to 3, and Fig. 5 shows Fig. 4 lengthwise on the section line 5-5 thereof.

In Fig. 6 we show a third type, in which the vanes are entirely controlled in their position at all times by a mechanical arrangement and a hydraulic arrangement. One may operate the other, and the hydraulic arrangement tends to decrease the friction necessarily associated with the mechanical arrangement to a minimum. Fig. 6 shows Fig. 7 on the section line 7--7.`

Fig. 6a shows a modification of the mechanical arrangement of Fig. 6.

Fig. 7 shows Fig. 6 on the vertical section line 7-7 thereof.

In Fig. 8 we have shown a modification, which might be used in any of the three types shown. Or in the pure hydraulic type, or in the pure mechanical type, or in the combined type of Figs. 6-7.

Fig. 9 shows diagrammatically that the chambers 11` and 2c in the rotor 2, containing uid under pressure and operating on opposite sides of the pistons connected with the vanes, may be connected continuously, without an intermediate valve 2e-e-e as shown in Fig. 2, with each other.

It further shows that the valves 2f and 2g may be omitted at either end of the circulating oil system.

It further shows by the dotted lines 2e-emee and 221; that the oil may be led from chamber 2c to the exit 22a.

Fig. l() shows diagrammatically that the exit 22a, either from chamber 11, or from chamber 2c, or from both chambers if they form together a single chamber, may be controlled by a centrifugal governor 2g-gg so that the pressure in either chamber or both chambers may be controlled in proportion to the centrifugal force, acting upon the pistons and their weights, and the fluid adjacent thereto, and tending to drive them to the periphery of the cylindrical element, the rotor. These modifications are described in more detail hereinafter in the description of the various modifications and their operation.

Returning to Figs. l to 3 for detailed description, in Fig. l, 1 is the stator, 2 is the rotor, 3 the inlet side, 4 the discharge type.

In the rotor we arrange a minimum of six vanes and a plurality of three vanes, radially from the center thereof. Each vane 5, 6, 7, 8, 9, 10, is attached to a rod 5e to 10e inclusive, which rod passes through a bearing 5d to 10d, and each rod is attached to a piston 5f to 1'0f. Each vane being attached to two rods and two pistons, the number of rods and pistons are l2 in the drawing.

The underside of these 12 pistons communicate with a central chamber 11, and the upper side of these A12 pistons communicate with a similar common closed chamber -Zclocated between the two main parts of the rotor, 2a, the outer part, carrying the vanes and the inner part 2b carrying the lower part of the cylinders 12 to 17, executed in duplo, in which the pistons 5f to 107c reciprocate.

The vanes 5 to 10 are at their outer end drilled lengthwise to receive rods 5a to 10a, which have at one side a curvature equal to the curvature of the inside wall of the stator 1, for the following reasons.

The axis of the rotor is indicated at -R- in the chamber r11, and the axis of the stator is indicated at -S- below it. If the vanes are in perpendicular position, the length of the vanes from tip to tip is exactly equal to the circular diameter of the inside of the stator 1, but in any other position the distance from tip to tip of these opposite vanes is slightly greater than the said circular diameter, depending upon two things, the difference in diameter of stator and rotor, and the angle of the vanes from the perpendicular position, in which the axis of the two opposed vanes go exactly through the axes -R- and -S.

Therefore the maximum difference occurs when two opposite vanes are in horizontal position in Fig. l. The shape of the path of the tips of the vanes describe a conchoidal or lymacon curve. The inside of the stator may have a pure circular shape for thepurpose of economic construction, but we do not intend to limit ourselves to this circular shape. If it appears that the construction proposed for certain fluids and certain functions, operates much better with a conchoidal curve for the inside of the stator, it may be equally built that way. In the construction shown therefore the lymacon shape or curve is slightly larger than the circular except at the top and bottom of the vanes (vanes in vertical position) and about 30 degrees on either side thereof. Therefore the bearings for the vanes shown in Fig. 3 control the exact position of the vanes only when approaching the vertical position of the vanes as shown. In any oblique and horizontal position the vanes could extend further than the circular shape but are controlled by the volume of the hydraulic fluid in one or both closed chambers 1 and 2c. This distance is however, so small that the centrifugal force pressing these vanes against this circular surface should be a minimum and balanced at that for all vanes exerting at any given position of the rotor a pressure on the stator. lf the inner surface of the rotor is a lymacon, the bearings and the hydraulic pressure should reduce the pressure to an absolute minimum.

In order to compensate for that very difference automatically and not entirely mechanically, the number of vanes has to be a minimum of three and the number of pistons a minimum of three, or the duplicate thereof which is 6, so that the amount of liquid volume, preferably oil here, of` course, remains a constant in any position Of the pistons and the vanes. That means either a constant volume of liquid in chamber lli, or a constant volume in chamber 2c, or a constant volume in both chambers 11 and 2c when in communication with each other, will create a nearly perfect balance on all the pistons and vanes simultaneously, because each piston and cylinder communicates with one closed chamber on one side of the pistons, or with a closed chamber common to all pistons on the other side thereof. Or the pistons communicate simultaneously with both sides `of the pistons while the total amount of fluid remains constant in both chambers.

In this first modification we rely entirely upon the constant centrifugal force exerted on the vanes by the rotation of the rotor, to fly outwardly, which tendency creates a flow of oil in chamber -Zcfrom half of the pistons flying outwardly towards the pistons moving inwardly to center R- in the rotor. Theoretically the fluid pressure being substantially equal in a closed chamber, the centrifugal force on half of the piston moving from the axis of the rotor would create a hydraulic force on the other half of the pistons moving towards the axis of the rotor in chamber 2c, which would create a theoretical substantial balance at least, which would tend to keep the clearance between the tips of the vanes and the inside of the stator a minimum, or rather a constant depending upon the volume of oil present in the chambers 2c and 11. In chamber 11 these forces are reversed in direction. If both chambers 11 and 2c are in communication with each other, the balance is even more perfect.

In order to establish said clearance definitely and positively we apply upon our compressor the construction shown in Fig. 2.

The sidewise ends of each vane 5 to 10 inclusive, is provided with an arm, indicated by 5b, each of which arms has centrally located on it three balls in a line, as shown in Fig. 2 lengthwise and in Fig. 3 transversely.

These balls 19 run in a continuous ball-race 19a, having an outer bearing on the casing -18, and are located in cups located on these l2 arms, 5b, of the six vanes.

The center of the ball race 19a is exactly concentric with the axis -S- of the stator 1, so that the tip of each vane is kept mechanically at the proper distance of 3 to 5 thousandths of an inch from the internal wall of the stator 1, if the inner surface of the stator has a lymacon curve. If it has a circular' shape, the hydraulic pressure (that is the amount of fluid in chamber 2c, or 11, or in both 11 and 2c when communicating with each other) will keep the tip of the vanes substantially in the circular curve, which is smaller transversely (in contradistinction to vertical direction within 30 degrees about from the center of the rotor) than the lymacon curve, As eX- plained the centrifugal force over that small difference of distance from the circular shape to the lymacon shape is not great and the fluid, constant in either chamber, or both chambers, equalises this centrifugal force so that the rubbing of the vanes on the circular shape of the stator is a minimum attainable.

The rotor is driven from either end of the shaft, 2e or Ze-e, extending from the inner element 2b, which forms a tight fit (shrunk cold into the hot member 2a) in the outer part of the rotor 2, so that the chamber 2c is leak-proof under pressure.

It is understood that if the diameter of the rotor is large enough to accommodate six radial pistons in the same transverse plane (as for instance illustrated in Figs. 4-5) that they may be of course arranged centrally of the vanes and the rotor, and if the arms 5b and ball bearings 19a and 19 are used the centrifugal force of these pistons would move the vanes radially outwardly towards these bearings. Such a` construction is considerably more economical to make and in smaller designs should be equally satisfactory.

In Fig. 2a. we show diagrammatically a thermostat 25, which we may use to move a needle valve 20 in a hydraulic circuit created by pump 23 in the pipes 21a and 21, leading respectively into the ends of the rotor, respectively 2e and Ze-e-e. The wall of the stator will heat-up immediately as soon as the vanes 5a to 10a rub on its inner surface, which would indicate that so much liquid or oil has disappeared from either chamber 11 or 2c, or both (in fact these two chambers 11 and 2c may be interconnected by a valve 2eee shown in Figs. 1 and 2, to establish communication between the two chambers, from the inner to the outer chamber 2c, in one modification) that the hydraulic control over the position of the vanes has disappeared, assuming that only the hydraulic control is used without the mechanical control of balls 19, and ball-races 19a, and ball-cups 19h whether the internal surface of the stator has a circular or lymacon curve. On the contrary if only chamber 11 were used and too much oil is in chamber 11 (either for the circular shape or lymacon shape of the stator) the vanes would rub on this surface and create heat in the cooling fluid for the stator. If only chamber 2c were used and too much oil is in this chamber, the vanes would not rub on this surface, but the rotor would leak and the efficiency would be low. Therefore the quantity of oil in either chamber. or both chambers should be exactly so much that the vanes would be kept at the proper distance from the inner surface of the stator. If this surface is circular the quantities indicated should be slightly smaller than when this surface is conchoidal. Therefore the pressure on the oil should be relatively small if valve 2g of Fig. 2 is used, and small quantities should be fed gradually into these closed chambers. The total surface and pressure on the pistons 5f to 10f in chamber 2c is slightly smaller than the surface on the same pistons (on the other side thereof) in chamber 11, but this is not a disadvantage if both chambers 11 and 2c communicate with each other so that the total volume thereof remains a constant at any position of the pistons and vanes. The best way should be to regulate the pressure on the spring of valve 2g by means of a centrifugal governor in proportion to the speed of the rotor and its centrifugal force, increasing the pressure on the uid by increased speeds. If this spring for valve 2g is not controlled, it should be of such a tension that at the highest speeds at which the pump is used, the centrifugal hydraulic pressure could not open it. In suchV a construction the amount of oil fed to either chamber, or both should be very small and very gradual, so that any increase in rubbing friction by the vanes would raise the temperature of the cooling fluid for the stator.

As soon as the cooling uid would go up in temperature, the coil 25a and the bellows 26 would be compressed closing the needle valve 20, and stopping the circulation or the feeding of oil into the chambers 11 and 2c.

The cooling fluid could be used only for this purpose in contact with the bearings 19 and 19a, because also these would raise in temperature if fluid leaked sufficiently from chambers 11 and 2c.

In Figs. l and 2 we have shown a valve Ze-e-e, which may open only under pressure in chamber 11 going to chamber 2c. However, there may be only an open passage (connecting without valve chambers 2c and 11) if a circulating oil-cooling system is adopted. Or both chambers may be under oil pressure from the same oillead as shown at 22a and 22b in Fig. 7. Or the pressure in both chambers may be regulated by the valve 2g as shown in Fig. 2. This valve may be controlled by a centrifugal governor as will be explained further on,

It is therefore particularly understood that the addition of the mechanism of Fig. 2 is only preferred when the hydraulic control is used, especially if the vanes are made very light as shown in the next Figures 4 and 5, in Which the ball race 19a and balls 19, as shown in Fig. 2, renumbered 117 in Fig. 5 may be omitted.

It is further understood that the oil perssure may be continuous and circulating in any type shown and variable in accordance with the centrifugal force, and circulating all the time to cool the rotor (an air cooler 21b may be combined with the circuit of Fig. 2a) also.

In so far as the hydraulic pressures on the pistons are nearly balanced in any position of the vanes and at any speed, a moderate continuous oil pressure would increase the total friction but little.

For a continuous circulating oil pressure, only a valve -Zfas shown in Fig. 2 may be used, or the valve 2f at the entry side in combination with the valve 2g at the exit side. Both valves having springs of a given tension, the oil pressure inside the rotor can be stabilized within accurate amounts. It is understood that if the two valves 2f and 2g in Fig. 2 close both going to the left, the tension of the spring valve 2g controls the pressure in the valves. If valve 2g would close in opposite direction, the tension of valve 2f would determine the pressure in the chambers 11 and 2c, and retain them both full of oil during the entire operation.

Another new feature of this type we will describe now. The vanes 5 to 10 if executed as large as shown about, can be conveniently used as additional pumping means as follows.

The underside of the pistons 5 to 10 are connected with the surface of the rotor may be a plurality of continuous open air holes 5g to 10g as shown, arranged in clockwise direction to the right of the vanes. y

If for counterclockwise rotation in Fig. l, the vane 10 has passed the edge 3a of the stator, the chamber below the vane 5 begins to increase and the air from inlet passage 3 enters this chamber through the air holes 5g. When this vane approaches the edge 3b or 3c, closing the chamber between the vanes and the rotor, the holes 5g still ll up the chamber under the vane until the next vane passes the point 3b or 3c, therefore it will be Completely filled practically. On the discharge side, as soon as the vane 10a passes the point 4a, the air under the vane is partially compressed, but will be forced out entirely until the vane has not only passed point 4b, but until the next vane 5a will have passed the point 4b also. And when passing point 3a, directly and immediately thereafter, the same chamber begins to ll up again. Not only is the volumetric efficiency of a given rotor and a given eccentricity of the rotor, greatly increased thereby, but the entire rotor is thereby automatically cooled off, and the oil circulation is cooled off. In case the device is used as a pump, it stands to reason that the point 4a cannot be removed a greaterdistance from the lowest point of the vane 8, because the vane 7a would decrease the volume between vane 7a and 8a before it reaches the point 4a, and if the device were or is used as a liquid pump, the liquid would be under pressure. Liquids being substantially incompressible, the eect of compression in any chamber would act as a tremendous brake. Equally the space under the vane is decreased in volume. fore it should be understood that this minor point should be kept in mind in` case the principles of the device disclosed would be used for an oilor water-pump, or any other liquid.

The construction of the opposing hydraulic forces together with the ball bearings 19, prevent any great friction anywhere, because the balanced oil pressures protect the bearings 19 from any `great centrifugal force. If the inner surface of the stator is made circular for cheap manufacture, the ball-bearings would be only effective near the top and bottom position of the blades as explained. If a little bit too much oil is pumped in chamber 2c, 11 or in both chambers, the friction of these ball bearings in these positions would force this small amount of oil out through valve 2g.

ln rotors of liberal dimensions it is preferred to combine with this feature, the mechanical means to drive the vanes outwardly in addition to the centrifugal force, as shown in Figs. 6-7, although the vanes shown in these figures and Figs. 4-5 are the very opposite of those shown in Figs. 1-3 and shown very thin.

Each type has advantages over the other, but the first type is the best type for engines needing the greatest amount of air volume, as for instance two stroke cycle diesel engines.

Although we have shown preferred constructions to regulate the volume of hydraulic uid in chambers 2c and 11, it is understood that other ways may be used creating a balance between the centrifugal force `acting upon the pistons 5f to 10f and the weights attached thereto. For instance the method described in the German Patent No. 658,560 of April 4, 1938, could be used provided it is combined with the present principle of having `a single closed chamber common to all the pistons of all the vanes, but not separately for each piston and vane as shown in said patent.

Another way would be to Vregulate the tension of the spring 2g in Fig. 2 in proportion to the centrifugal force by means of a centrifugal governor as shown diagrammatically in Fig. 10.

It is specifically understood that we might control this pressure in any other way as for example by a governor. At low speeds in which the centrifugal force is low, we might cut off or eliminate the oil-pressure entirely by means of a centrifugal governor, which is shown in Fig. l0. It would cut olf all oil-pressure by means of a governor-valve and open a passage for drainage, and at a predetermined speed it would shift the governor valve to a position in which oil-pressure is admitted to, or rather retained in either 'one or both of these chambers, communicating with either one side or both sides of the hydraulic pistons. However, if in certain types it appears advantageous to have the governor Zg-g-g (and spring Zg-g) in Fig. l() control the hydraulic pressure throughout the range of all speeds, such an arrangement should Therethen be applied. These governor valves have been shown by applicant, Barkeij, in his prior applications No. 346,258 of July 17, 1940, No. 53,918 of October 1l, 1948, and No. 138,411 of January 13, 1950, all now abandoned. cation 346,258 is closely referred to, because its hydraulic and mechanical principles are most closely related to my Patent No. 2,209,012, referred to several times in the subsequent applications referred to hereabove. lts coordinating principle between the hydraulic and mechanical means is one of the crucial points.

In the second type shown in Figs. 4 and 5, we may use only the hydraulic pressure and omit the balls 19 and ball-race 19a, and ball-cups 19h, by lightening the vanes to a minimum, as we will now describe.

In Fig. 4, the numbers 101 to 1114 describe the same essential parts as shown in Figs. 1 to 4. Instead of screwing or welding the rods Se to 10e in their respective vanes 5 to 10, we prefer here to extend the rods 105 into the body of the rotor itself, having a bearing therein and sealing the oil at 105 above the pistons 111 to 115 of each vane. The vanes 108 are slidingly arranged in these two or more rods 105 and have a bearing also in the body itself, beyond the two rods of each vane. The center plane of the vanes 108, and their lower ends 1416 do coincide with the axes of the two rods 105, having a diameter substantially in excess of the width of the lower ends of the vanes 166 as shown in Fig. 4a.

lf these vanes are made of magnesium, and the diameter and speed of the rotor is not too high, the arms 10611, balls 117 and ball race 106C can be dispensed with, because the centrifugal force will not be too high and therefore the friction not too high. For a durable compressor, however, it is not advisable to dispense with these items.

It is possible to make an alternative design, retaining all other features, as will be described later.

The rotor is again divided in two parts 10251 and lltlZb, and a closed chamber 109 between the two, and a central closed chamber 116 below the pistons 105, and 111 to 115 inclusive.

The two chambers may communicate with each other continuously for a lubrication-cooling-system, they may be separated by a valve as shown for Figs. 1 to 3. The) may be separately fed as shown in the following Figs. 6 and 7. The pistons 111 to 115 can be made of smaller diameter, as shown, having the added advantage that all six pistons may be arranged radially on each end of the rotor in the same transverse plane instead of in staggered position as shown in the rst 3 figures.

Furthermore a plurality of 3 to 4 pistons with rods may be applied lengthwise of the rotor for added support of each of the vanes.

It is further understood that the rods of the pistons and the vanes may be solidly attached to each as shown in the rst three figures, so that the weight of the free reciprocating masses in the rotor are kept a minimum, or rather zero. Free means here, free from centrifugal forces pressing them on the stator. This modification has been illustrated by us in Fig. 8.

Another alternative construction is that the width of the outer vanes 10S- 107 can be greatly decreased up to the horizontal line 106b shown in Fig. 5, if the vanes are formed solidly together with the rods of the pistons 105, 111 to 115, because in that case the outer portions 107-108 slide then in the rotor only instead of in the slits of the rods and in the rotor as shown in Fig. 4a.

It is understood that the Figs. 5 and 4 show the fundamental features of the hydraulic and mechanical control of the vanes to reduce the friction of the vanes on the stator to a minimum, and it is superfluous to state that much material can be eliminated in order to reduce the total weight of the rotor to a minimum.`

The purpose of the drawing is merely to show these fundamental features in their most simple form, also for the purpose of formulating properly the appended claims in their broadest and simplest form.

1n the description herein, only the appli-` In Figs. 6 and 7 I show a third type, in which the vanes are controlled hydraulically and mechanically at the same time. 201 to 204 represent again the same parts as in the prior figures.

The pistons 205 are sliding in cylinders drilled in the body 202-b of the rotor. The rods 205a above these pistons slide in bearings in the outer part 202-a of the rotor. The rods 205k below the pistons have at their lower ends a broadened or extended foot S-c sliding sideways over bronze pieces 20S-d, rotating over the stationary inner shaft 206, located inside the closed chamber 202d.

Again, if the vanes 207 are in perpendicular position, their tips are exactly from each other removed the length of the diameter of the stator 201. If these vanes have rotated clockwise to the position shown at 212 in Fig. 6, 60 degrees further, their axes are located as shown by the line R-R going through the axis of the rotor 202. The line S-S, next to it, is going through the axis of the stator, so that it is evident that on the scale shown, the distance on the line RR from tip to tip of opposite vanes is slightly less than the conchoidal or lymacon shape, which the tips of the vanes tend to describe. Therefore the stationary shaft 206 has to be given either a slightly smaller circular diameter all around or has to be made slightly conchoidal in order to compensate for this variation. When the vanes have moved 90 degrees further to the horizontal position this ditference is a maximum.

As shown in Fig. 7 the shaft 206 may be anchored at one end in the stator and at the other end in the inner part 20211 of the rotor, as shown at 20Gb.

If the hydraulic pressure would at any time not be sufficient for the pistons 205 on account of the hydraulic friction to reach their proper position by centrifugal force only, the shaft 206, shoes 205d operating on the feet 205C of the rods 20S-b, attached to the pistons 205, would move the vanes 206, in cooperation with the balls 207 on the arms 206a of the vanes, exactly into their proper position except forthe little diiference in diameter in certain positions of the vanes. If the pump 23 of Fig. 20. keeps a constant pressure by means of valve 2f as shown in Fig. 2 inside the chambers 202e and 202-d of the rotor of Figs. 67, the hydraulic pressure is bound to move the pistons that small distance further and yet the bearings 208 will prevent the vanes from touching the stator at any time. In Fig. 6a we show a modification thereof.

In order to simplify and cheapen the structure, it is possible to provide the shoes 205C, which are opposed to each other, with connecting straps 205e, which provide a slight play, as shown at 205i, encircling the shaft 206 without touching it, in order to dispense with arms 206a and bearings 207 as shown in Fig. 7. The hydraulic force in the outer chamber is then relied upon to prevent the tips from touching the stator, or to keep always at any times a minimum clearance or seal between the two.

It is understood that the construction of the stationary shaft 206, shoes 2055/, rods 2051; of Figs. 6-7, may be equally applied on types shown in Figs. 1 to 3 and Figs. 4-5.

It is understood that instead of the thermostat of Fig. 2a, a valve 2f, as shown in Fig. 2, with a predetermined spring pressure may be used.

It stands to reason that the oil pressure system of any prime mover, as an internal combustion engine, may be used to provide an increasing pressure in said two closed chambers in said rotor, so that with increasing centrifugal force the oil pressure increases proportionally. However, the most important point is to keep the volume of oil exactly constant notwithstanding the leakage bound to take place all the time, and a single valve 2f is the cheapest and most reliable means to effect that constant volume and thereby automatically an almost constant pressure independent of the speed of rotation, except for the increased friction causing increased pressures.

A particular feature is shown in Fig. 2a not described before, but we will describe it here now as an alternative structure, which has certain features which may make it preferable to any other variation described.

The bellows 26 may be upwardly connected with a valve in general or a needle valve in particular 20a, which may control reversely the amount of cooling liquid leaving or going to any part of the stator to cool it. If the loweror bottom-valve controls the quantity of oil going to the rotor (chambers 11, and/or 2c) the upperor top-valve may control reversely the amount of liquid going to or leaving the stator. This might make the total control that much more sensitive. If the friction would cause the liquid to rise in temperature sufficiently to heat up the liquid, cooling the stator or any part connected with l' it, and the bellows would expand, it would simultaneously impede the amount of cooling liquid leaving or entering the stator, which fact would at the same time increase the rise in temperature of the cooling liquid that much faster, and the action of admitting the oil to the chambers 11 and 2c that much quicker.

This extra feature would not be only applicable in the present structure, but would nd a wide field of application elsewhere, where thermostats are used, for instance in the refrigeration field to name only one.

It would be useful further to regulate the two valves 20 and 20a in such a relation, that a minimum of oil is admitted by the needle 20 always to compensate for the normal loss of oil where the pistons and the rods lose it, so that an almost constant volume of oil independent of the speed of rotation is obtained. This volume depends either on the circular shape or conchoidal shape of the inner surface of the rotor. If conchoidal the volume is slightly greater than when the surface is circular. In order to simplify the claims to a minimum of words, the arms 5b of the first type shown in Figs. l to 3, have two angles. The first 90 angle is formed towards the axis of the rotor at 90 to the longitudinal axis of the vane, then a second angle is formed to said rst angle, and the axis of this last part is parallel to the axis of the vane proper.

In the appended claims we define these arms and vanes as vanes having two ninety-degrees-angle arms at the outer ends thereof.

In the second type of Figs. 4 and 5 these vanes have v similar arms 106a which are covered by the same generic claims.

In the third type of Figs. 6-7, these vanes are also present and have similar arms 206a, which are covered by the same generic claims. In the third type an additional central shaft 206 is added, which may co-operate with said arms to effect a single result, to effect a minimum of friction or clearance with the stator.

We claim:

l. In a positive type of displacement pump, in combination a stator with a cylindrical inner surface and a rotor with a cylindrical outer surface of smaller diameter than said inner surface and having an axis eccentric to the inner wall of said stator, a plurality of vanes radially arranged on said rotor from the center thereof, pistons in cylinders arranged radially in said rotor, said vanes in operative connection with said pistons, a closed fluid pressure chamber communicating with each of said piston cylinders on one side of said pistons, and another closed uid pressure chamber communicating with each of the piston-cylinders on the other side of said pistons.

2. The combination of claim 1, in which the number of vanes is at least three, a valve in a passage between said two chambers opening under pressure from one of said chambers to the other chamber, and means to feed oil through a second, spring operated non-return valve to the first of said chambers.

3. The combination of claim 1, in which the number of vanes is at least 3, a passage between said two chambers, and an oil-circulating system connected with at least one of said chambers, to establish a predetermined amount of oil-pressure in said chambers.

4. The combination of claim 1, in combination with means to feed oil through a non-return valve to one of said chambers, a passage between said two chambers to equalize the pressure in said two chambers so that said two chambers are kept continuously under given pressures depending upon the speed of rotation of the pump.

5. The combination of claim 1, in which each of said vanes are provided at their outer ends with arms, each arm provided with a plurality of cups for a plurality of balls, said balls running in a ball race arranged on said stator.

6. The combination of claim 1, in combination with a fluid cooling system for the walls of said stator, an oil-circulating system for said rotor, a conduit connecting said fluid cooling system with a thermostat, a

valve operated by said thermostat in said oil-circulating system connected with at least one of said closed chambers in said rotor, said thermostat closing said valve for admitting oil-pressure to said chambers and pistons as long as the temperature of the fluid of said fluid cooling system exceeds a predetermined amount.

7. In a rotary pump of the vane type, a stator, a rotor having a plurality of cylinders and pistons arranged in said rotor, said pistons moving vanes in said rotor, the said rotor divided in an outer part in which said vanes slide, and an inner part, in which said pistons slide, said two parts forming a closed chamber, communicating with all the piston chambers on one side of said pistons, and means to maintain a uid pressure in said closed chamber.

8. The combination of claim 7, in combination with means in operative connection with said vanes to keep said blades at a predetermined distance from the inside surface of said stator.

9. In a rotary pump of the vane type, a stator and a rotor therein, a plurality of cylinders and pistons arranged in said rotor, said pistons moving vanes in said rotor, a closed chamber connecting with one side of all the pistons in said cylinders, a second closed chamber connecting with the other side of all the pistons in said cylinders, and means to maintain a uniform uid pressure in both of said chambers.

10. The combination of claim 9, in combination with means connected to said vanes to keep said blades at a predetermined distance from the inside surface of said stator.

11. ln a rotary pump of the vane-type in which the rotor is placed with its axis eccentric to the inner surface of the stator, which has either a circular inner surface, mechanical means to retain the vanes of said rotor at a predetermined distance from said inner surface, said rotor comprising hydraulic means operative on all of said vanes simultaneously in any position to keep the vanes of said rotor at a predetermined distance from said inner surface, both of said mechanical and hydraulic means co-operating to retain said blades at a predetermined position from said inner surface when rotating.

12. in a rotary pump of the vane type, in which the rotor is placed with its axis eccentric to the inner surface of the stator, said rotor comprising a hydraulic closed uid chamber communicating with pistons radially arranged in said rotor, said pistons connected to vanes, the centrifugal force operating upon said pistons and fluid in said closed chamber to drive said vanes towards the inner surface of said stator in such a way that said vanes are driven towards said inner surface with a force which is substantially equalised over said vanes in any position of said vanes.

13. A rotary mechanism, comprising a rotor having cylindcrs and pistons arranged radially therein, a closed fluid chamber communicating with one side of all of said pistons, said pistons connected with weights forming solid units tending to move radially from the axis of said rotor to the circular surface thereof, but the fluid pressure in said chamber distributing the uid pressure equally over said pistons and weights, and means to introduce oil under pressure into said chamber to compensate for said cen iii trifugal force on said piston, weights and iiuid, and said oil pressure being suilicient to reciprocate said pistons against the centrifugal force towards the axis of said rotor.

14. A rotating mechanism comprising a cylindrical element' having pistons and cylinders arranged radially therein in at least one plane perpendicular t0 the axis thereof, said pistons having a substantial weight and forming solid units tending to move radially from the axis of said element, a closed fluid chamber communicating with one side of all of said pistons, preferably that side nearest the peripheral cylindrical surface of said element, means to introduce oil under pressure into said chamber which is sufficient to move said pistons towards the axis of said element at any rotative speed thereof.

15. A rotating mechanism comprising a. cylindrical element having cylinders and pistons therein arranged radially from thc axis thereof, two closed chambers in said element, one of said chambers communicating with one side of said pistons which is nearer the periphery of said element, the other of said two chambers communicating with the other side of said pistons, which is nearer the axis of said element, means to introduce oil under pressure into said chambers to move said pistons either towards the periphery of said element or towards the axis thereof during rotation.

16. The combination of claim l5, in combination with a communicating passage between said two chambers.

i7. ln a rotary compressor or pump, a stator and a rotor, a plurality of pistons in cylinders arranged radially from the axis of said rotor, said pistons connected to vanes arranged near the periphery of said rotor, one uid pressure chamber connected with both sides of all pistons therein, means operatively connected with said vanes and pistons having a bearing concentric of said stator, to retain said vanes at a predetermined distance from the inner surface of said stator, and means to maintain a iiuid pressure in said chamber to counteract the centrifugal force operating on said pistons and vanes tending to drive said pistons and vanes to the peripheral surface of said rotor, and means to cool said stator with a fluid.

18. The combination of claim 17, in which said fluid pressure is regulated by a thermostat, which is operated by the temperature of the fluid cooling said stator.

19. ln a rotary pump, a stator and a rotor, said stator having an inner surface, and said rotor having an outer cylindrical surface of substantially smaller diameter than said inner surface, a plurality of vanes arranged on said rotor, mechanical means comprising a bearing concentric with said inner surface to retain said vanes at a predetermined distance from said inner surface during rotation, said vanes connected with pistons operating in cylinders arranged radially of said rotor, and fluid pressure means operating on both sides of said pistons to control the centrifugal force operating on said vanes and pistons, tending to drive them towards the periphery of said rotor.

20. The combination of claim 19, in which said fluid pressure means comprises a valve operated by a centrifugal governor to control the pressure on all of said pistons simultaneously in the same degree.

2l. The combination of claim 19, in which said fluid pressure means comprise a circulating oil system under pressure.

22. In a rotary pump of the vane type, in which the rotor is placed with its axis eccentric to the inner surface of the stator, which has a conchoidal inner surface, mechanical means to retain the vanes of said rotor at a predetermined distance from said inner surface, said rotor comprising hydraulic means operative on all vanes simultaneously in any position to keep the vanes of said rotor at a predetermined distance from said inner surface, both of said mechanical and hydraulic means izo-operating to retain said blades at a predetermined position from said inner surface when rotating.

23. A rotating mechanism comprising a circular body having cylinders and pistons arranged radially from the axis thereof, mechanical means to retain said pistons at a predetermined distance from the axis of the rotating mechanism, said rotating mechanism comprising hydraulic means operative on all of said pistons simultaneously in any position to keep the pistons in said rotary mechanism at a predetermined distance from the axis of said mechanism, both of said mechanical and hydraulic means co-operating to retain the said pistons at a predetermined position from said inner surface when rotating.

24. The combination of claim 23 in combination with means to control said hydraulic means, said control means depending in their controlling function upon the speed of rotation of said rotating mechanism.

25. A rotating mechanism comprising a circular body, having cylinders and pistons arranged radially from the axis thereof, at least one hydraulic pressure to operate in said cylinders and pistons to move said pistons towards the axis of the rotating mechanism against the centrifugal force operating on said pistons, said hydraulic pressure operating upon all pistons simultaneously to keep said pistons at predetermined distances from the axis of the rotating mechanism, and additional mechanical means to co-ordinate the motion of said pistons so that these distances are exactly co-ordinated, and so that said hydraulic pressure and mechanical means do co- Operate.

26. The combination of claim 25, in combination with means to control said hydraulic pressure on said pistons, said control means depending upon the speed of rotation of said rotating mechanism.

27. A rotating mechanism, comprising a circular body, having cylinders and pistons therein arranged radially from the axis thereof, at least one hydraulic pressure to operate on said pistons in said cylinders, at least once every revolution of said body, to move said pistons against the centrifugal force, operating on said pistons continuously, towards the axis of the rotating mechanism, said hydraulic force operating on said pistons to keep said pistons at predetermined positions with respect to said axis during each single revolution, and additional mechanism to co-ordinate the motion of said pistons so that these distances are exactly coordinated hydraulically and mechanically, said pistons actuating other elements arranged on said rotating mechanism subject to centrifugal force.

References Cited in the file of this patent UNITED STATES PATENTS 609,028 Jones Aug. 16, 1898 824,647 Hamann lune 26, 1906 1,367,554 Leitch Feb. 8, 1921 1,669,779 Reavell May 15, 1928 1,752,093 King Mar. 25, 1930 1,905,521 Steiner Apr. 25, 1933 1,939,970 Tuess Dec. 19, 1933 1,940,384 Zoller Dec. 19, 1933 2,027,594 Huff Jan. 14, 1936 2,124,539 Erelsford et al. July 26, 1938 2,193,581 Clokey Mar. 12, 1940 2,264,616 Buckbee Dec. 2, 1941 2,469,510 Martinrnaas, Jr. May l0, 1949 2,473,309 Stephens June 14, 1949 2,545,238 MacMillin et al. Mar. 13, 1951 2,607,298 Nicolas Aug. 19, 1952 FOREIGN PATENTS 100,943 Germany Jan. 20, 1899 318,638 Great Britain Oct. 16, 1930 658,560 Germany Apr. 4, 1938 

